One of the main problems in recovering any waste materials is the necessity of sorting the waste stream and separating for example plastic materials from non-plastic and different plastics contaminating materials or for example a desired plastic material from other plastic contaminating materials. For example when attempting to recover the plastics material in plastic bags returned to supermarkets, it has been found that such lots of bags returned may contain contaminants such as paper, fruit remnants, metal cans, bottle caps, packaging and other random materials. It is prohibitively expensive to sort these contaminating materials prior to reclaiming the plastic.
It has been proposed in the prior art in recovering plastic to add to the plastic as processed in a mixer a predetermined amount of refuse which has been dried and ground. An example of such a process is found in U.S. Pat. No. 5,035,189. Of course with this process the refuse must have been presorted dried and ground prior to being dispensed into the the mixer of the process. This luxury is not afforded generally in the real world and as such the teachings of U.S. Pat. No. 5,035,189 is only of particular application when one knows the constituents of the product streams. There is no discussion within this reference as to the encapsulation of each finally divided particle within the waste stream. Further the contaminating material which is undesirable does not arrive in a random manner.
Other examples of plastic recovery systems or components are found in U.S. Pat. No. 3,421,405, U.S. Pat. No. 4,626,189, U.S. Pat. No. 4,824,627 and U.S. Pat. No. 4,187,352. Like U.S. Pat. No. 5,035,189 all of these references require knowledge of the product streams; that is to say none of the contaminating material arrives randomly with the plastics material to be recovered or reclaimed.
Applicant is also aware of U.S. Pat. No. 4,874,566 issued Oct. 17, 1989 and U.S. Pat. No. 5,032,072 issued Jul. 16, 1991 and claiming priority from U.S. Pat. No. 4,874,566, being a divisional thereof, and teaching the processing of thermoplastics received in a non cleaned and non sorted state. The final output of said method or process includes molded finished product. Applicant is also aware of U.S. Pat. No. 4,185,784 which teaches the use of a roller extruder device which crushes non plastic waste carried in the plastic received. No comminuting to a fine grind of the undesirable contaminants is taught however in either reference.
Nowhere within the prior art is there taught the handling of unsorted contaminated plastic materials wherein the method and the process includes steps and an apparatus for comminuting plastics material, having undesirable contaminants therewith, while said plastics material is in a plasticized state. This process provides a distribution of the contaminants within the plasticized material and hence the final products recovered and contaminants of a much reduced particle size so as not to affect unduly further processing or use, of the recovered or reclaimed plastics material in a commercially viable process. This process is therefore superior to any process or method or machine found in the prior art.
It is therefore an object of the invention to provide a process for recovering plastic materials that is considered waste because it is considered to have unsorted undesirable contaminants associated therewith (for example contained therein) wherein the output of said processing includes finely dispersed particles of the contaminants encapsulated within the recovered plastics material which contaminants do not adversely affect the ability to further process the recovered or reclaimed plastics material into viable products.
It is a further object of the invention to provide a method for accomplishing the above objective, and the finished products of both the method and the process.
It is yet a further object of the invention to provide an apparatus, machinery and components therefore for comminuting plastics materials having carried therewith undesirable contaminants, the comminuting of the refuse occurring while the plastic is in a plasticized state.
Further and other objects of the invention will become apparent to those skilled in the art when considering the following summary of the invention and the more detailed description of the preferred embodiments illustrated herein.